February 2012 Issue - Target Shooter Magazine

THE HANDLOADING BENCH
308 Winchester Rides Again Part 2
By Laurie Holland
while the company simultaneously carried out its
own performance evaluations. With both parties very
happy with the results, Lapua Nammo Oy launched
its new SRP case branded and headstamped with the
‘Palma’ name with the US NRA’s approval in early
2010, supplies reaching our UK importers, Hannams
Reloading Limited, that autumn.
Remington 308 UBBR (Unformed Basic Bench Rest)
case which also employed the small primer/small dia.
flash-hole combination.
It was alleged all sorts of problems would be
generated including variable performance, sensitivity
to temperature variations, even hang-fires. A
common refrain was: ‘Been there, done that, gave it
up as a bad idea!’ The critics were, probably still are,
generally of the view that the small rifle primer (SRP)
is only marginally adequate for this size of cartridge
and weight of powder charges,
that marginal status tipping
over the line into inadequacy
under certain conditions to give
unpredictable and unsatisfactory
performance.
THE HANDLOADING BENCH
308 Winchester Rides Again Part 2
By Laurie Holland
The Palma Match shield is topped by a stylised eagle and wreath emblem as reproduced on the Sierra ‘Palma’
MatchKing bullet carton. This is one of the very few products allowed to use the name and image.
Canny long-range .308W users look for ‘mild’ LR primers that perform
consistently. Some batches of the Russian Tula manufactured PMC / Wolf brand
LRPs are highly prized.
Controversial
Not everybody welcomed this variant with open arms.
A number of shooters questioned whether it was
‘legal’ under the Palma, Fullbore/Target Rifle and F/TR
governing body’s (ICFRA) rules. Here is the relevant
section:
T2.19.1. Cartridge Dimensions: With the exception of
overall loaded length, cartridges must comply with
the SAAMI or CIP cartridge specifications for .308
Winchester or .223 Remington respectively.
The US SAAMI standards body, which has technical
responsibility for this cartridge, advised that the
primer type is not prescribed in its specifications and
large or small is immaterial to conformity decisions.
Other equally serious but even more numerous
criticisms came from shooters who had knowledge,
either personally or second-hand, of the old
On this issue of 308 UBBR brass
versus the Lapua Palma Match
version, one must consider
that while the ‘UBBR’ was
manufactured with 308 Win
external dimensions, it was
in some respects a different
animal. It was drawn with
exceptionally thin walls as its
purpose wasn’t to be shot as
.308W but to be a ‘basic case’
for reforming into the smaller BR Remington design
and various wildcats. The ultra-light construction
gave it significantly greater internal capacity than
standard 308W brass and ideally required a tighter
than ‘minimum-SAAMI’ chamber as well as the use of
a custom or neck-bushing sizer die. The UBBR cases
date from a quarter century ago too, as does much
of the critics’ experience with them and propellant/
primer technology has certainly not stood still over
that period.
Here’s what the project’s instigator, Tom Whitaker had
to say in 2010 in response to sustained criticism on the
US Rifle Teams’ Long-Range Shooting Forum:
”After 25+ years of using the Remington BR cases in
308 and 6.5 calibers I have some experience using the
small primer case. We should all agree there are many
factors that contribute to loading accurate ammunition.
It is a well known fact that primers are one of the most
important of these factors as they start the whole
process going. What I found over the years is that there
is a large variance in ignition using large rifle primers.
Not just from brand to brand but from lot to lot within
the same brand. No big revelation here, I’m sure we all
have experienced this. Using small rifle primers I have
found very little to no variance between lot to lot within
a brand and minor variance from brand to brand. This
equates to a much easier time developing a precision
load and sustaining that load over a long period of
time. Other factors affected by this are the reduced
need to stock up on a certain component (primers can
deteriorate over time) and less barrel wear wasted in
testing.
...So, what’s the point? It is not 3-5 fps better ES
(although I have found it to be better than that), nor is
it that this case will produce ammo more accurate than
the best LRP case loads (a great load is a great load
no matter what you use). The big gain, in my opinion,
is that it is much easier to find that great long range
load with these SRP cases than it is with LRP cases.
Everyone has access to this case now use it if you want
or not, the choice is up to you.”
The US Palma team reported that the SRP brass
reduced velocity spreads (ES) by around 30%,
sometimes more, with its standard load of the 155gn
Sierra ‘Palma’ MK over Hodgdon VarGet. 15-round
strings recorded ES values of 12-18 fps and SDs of 4-5
fps. The sole downside was a reduction in the MV but
this could be rectified by adjusting the charge weight.
Four SRP brands were tried, purchased over the
counter in ordinary gunshops and all performed
well with little lot to lot variation. Low temperature
questions were faced head on by placing SRP
ammunition in a freezer overnight and test firing it
over a chronograph immediately afterwards which
was done without any serious or safety related
problems such as hang-fires, although a reduction in
the average MV was (unsurprisingly) recorded.
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